Medical devices, for example urological medical devices such as urinary “Foley” catheters, urethral stents and ureteral stents, among others, have been useful for treating a variety of medical conditions. Ureteral stents help maintain urine flow from the kidneys, through the ureter, to the bladder following many common urological procedures. It is estimated that over 135,000 people were hospitalized for kidney stones and over 17,000 kidney transplants took place in 2007—both procedures frequently necessitating ureteral stents. Such stents facilitate kidney stone/fragment passage, act as scaffolds for healing in cases of ureter laceration or reconstructive surgery, prevent ureteral strictures, and facilitate drainage following kidney transplant or during malignancies. While some of these stents are used temporarily, others are left in the body for weeks or months. During this time, the stent becomes both encrusted with crystalline material of calcium and magnesium, and covered with a bacterial biofilm that may increase pH. These two effects often work together. Bacteria in the biofilm can raise urine pH, which in turn, precipitates calcium salts onto the stent. However, they also work distinctly—even eliminating bacteria does not necessarily reduce encrustation.
Regardless of the mechanisms of encrustation and biofilm formation, there is a need for the development of implantable/insertable devices that are capable of preventing, reducing and/or treating encrustation and biofilm formation caused by the implantation or insertion of such devices into a patient's body.